This invention pertains generally to inertial rate sensors and, more particularly, to an inertial rate sensor and method with improved clocking.
Inertial rate sensors are used in a wide variety of applications including aircraft navigation, the guidance of missiles and spacecraft, and automotive stability control systems. In many of these applications, safety is critical, and measures must be taken to guard against failures of the sensor.
It is in general an object of the invention to provide a new and improved inertial rate sensor and method.
Another object of the invention is to provide an inertial rate sensor and method with improved clocking.
These and other objects are achieved in accordance with the invention by providing an inertial rate sensor and method in which a drive signal is applied to a vibratory rate sensing element, a pickup circuit is coupled to the rate sensing element for providing an output signal corresponding to movement of the rate sensing element, digital logic calibrates the rate sensor and detects the occurrence of faults in the rate sensor, the rate sensing element is utilized as a frequency reference for providing a system clock signal for the digital logic, a fixed phase relationship is maintained between vibration of the rate sensing element and the system clock signal, the system clock signal is filtered to eliminate responses to spurious transitions during a period following application of operating power to the sensor, and the digital logic is reset in synchronization with the system clock signal.